Shiny dynamically create actionButtons #observeEvent #renderUI #uiOutput

shiny-dynamic-actionbuttons.R

# UTILS -------------------------------------------------------------------

#' Generate input IDs for Shiny for dynamically generated elements
#'
#' @param prefix a meaningful text for the element e.g. button, table, slider etc.
#' @param id increase iteration from e.g. a loop.
#' @noRd
shinyInputId <- function(prefix, id) {
  paste(prefix, id, sep = "_")
}

# DATA --------------------------------------------------------------------

mtcars <- datasets::mtcars

# APP ---------------------------------------------------------------------

ui <- fluidPage(
  h1("Cars"),
  br(),
  lapply(seq(nrow(mtcars)), function(i) {
    uiOutput(shinyInputId("button", i))
  })
)

server <- function(input, output, session) {

  lapply(seq(nrow(mtcars)), function(i) {

    Name <- rownames(mtcars)[i]
    gen.input <- shinyInputId("button", i)

    output[[gen.input]] <- renderUI({
      actionButton(
        inputId = gen.input,
        label = Name
      )
    })

    observeEvent(input[[gen.input]], {
      print(paste("You clicked", Name))
    })

  })

}

shinyApp(ui, server)